TESTFA/CCD

The command does a series of tests on a catalogue of low count flats. The whole is split in two smaller tests, commands TESTF1/CCD to TESTF2/CCD that do the following:

1.

Test F1: Creation of the combined flat frame, using only those flat frames in the input catalogue that have exposure times falling within the allowed range. The combined flat is corrected for the bias offset. The bias offset is taken from the keyword BIASMEAN filled by the command TESTB/CCD. The combined flat is loaded on the display.

2.

Test F2: Thereafter all pixels in the stacked master flat frame that show values less than thresh times the median counts in the frame are listed. Only pixels within the area contained in `area' are considered and repetitions of cold pixels in the increasing y coordinate are not listed.

The complete TESTFA/CCD command produces the following:

• A combined low count flat frame corrected for the bias offset;
• An ASCII and MIDAS table containing traps and other defects in the stacked master flat frame that show values less than N times the median counts in the frame. Only pixels within the input area are considered and repetitions of cold pixels in the increasing y coordinate are not listed.

The combined low count flat field is corrected for the mean bias offset, stored in the keyword BIASMEAN, filled by the command TESTB/CCD. The user can also supply this keyword with the name of the combined bias frame, also produced by TESTB/CCD. In that case this frame will be used for the bias correction.